1. Field of the Invention
The present invention relates to a new and improved grid for an opening roll or roller of a spinning machine for processing fibers, for example, a cleaning machine or a card or the like comprising a plurality of grid bars or rods provided in a grid frame and arranged along the circumference of the opening roll or roller. In the environment of a card such opening roll or roller is also referred to as a licker-in or licker-in roll.
The present invention also relates to a fiber cleaning apparatus for a spinning machine for processing fibers equipped with the new and improved grid of the present development.
2. Discussion of the Background and Material Information
Grids for such type textile machines are well known in this technology. For example, Swiss Patent No. 464,021, granted Oct. 15, 1968, and also cleaning machines of the present assignee sold worldwide under the commercial designation Type ERM B5/5 disclose a downwardly pivotable grid to which there are secured a plurality of knifes or cutters for removing contaminants from cotton. The cotton is moved past the knifes by an opening roll provided with teeth, also referred to as clothing. Adjustable guides, for example, sheet metal guides, are provided at the spine or rear side of the knifes, so that by virtue of the adjustability of the guides there can be set the guidance of the cotton lying on the clothing of the opening roll from knife edge to knife edge in such a manner that there is realized a settable elimination of contaminants from knife to knife. These knifes are fixedly secured to the grid which, in turn, can be pivoted away from the opening roll.
Furthermore, United Kingdom Patent Application No. 2,053,995, published Feb. 11, 1981, depicts and describes the possibility of positionally adjusting pivotable knifes by means of a grid or grill such that there can be altered the angle of attack of such pivotable knifes with respect to the circumference of the opening roll. To that end, the knifes are pivotably mounted at stationary pivot shafts at their front end portions where there are located the knife edges, and the rear end portion of each knife is pivotably mounted in the grid or grill. Thus, by moving the grid or grill in the circumferential or peripheral direction of the opening roll there can be altered the angle of attack of the knifes with respect to the circumference of the opening roll, which circumference is also referred to as the beater circle.
Both types of equipment relate to older generation machines which at that time were intended to process less contaminated cotton at a lower production capacity or output.
However, in the last fifteen years the spinning machine industry has strived to increase the production capacity of each individual type of machine with the objective of being able to process more contaminated cotton, especially cotton containing fine contaminants or rejects like, for example, so-called seed coat fragments.
Additionally, persons skilled in spinning technology are well aware of the fact that, on the one hand, the finer the contaminants the more difficult it is to remove such fine contaminants from the cotton fibers which usually are markedly intertwined with one another and, on the other hand, the danger of damaging the fibers increases in direct relationship to an increase in the production capacity of the relevant machine.
Increasing demands are thus placed by the spinning machine industry upon cleaning machines or elements which perform cleaning functions, since a fundamental prerequisite for the cleaning of cotton is the positive disengagement or disentanglement of the previously mentioned intertwined cotton fibers which form cotton flocks, but however, without thereby altering, to the extent possible, the cotton fibers, for example, reducing the length of the cotton fibers.
Impacting or beating cotton flocks against knife edges, as occurs in the aforementioned cleaning machines, indeed produces a cleaning action at those fiber flock surfaces contacting the knife edges, but, on the other hand, opening of the fiber flocks only occurs in a subordinate fashion during such treatment